package org.wamblee.socketproxy; 

/**
 * Copyright (c) 2005 UPS_SCS NL
 * 
 */

public class Barrier {

    private int _countLeft;

    public Barrier( int aCount ) {
        _countLeft = aCount;
    }

    public synchronized void block( ) {
        _countLeft--;
        if ( _countLeft < 0 ) {
            throw new IllegalStateException(
                    "Barrier count became negative, programming error" );
        }
        notifyAll( );
        while ( _countLeft > 0 ) {
            waitUninterruptable( );
        }
    }

    private void waitUninterruptable( ) {
        try {
            wait( );
        } catch ( InterruptedException e ) {
            // ignore.
        }
    }

}